I did not view "St. Elsewhere" when it first ran from 1982 - 1988, perhaps because that was the period when I was usually at work 12 hours a day (most especially in 1982), although I recall being aware of it and its principal leads, Ed Flanders, Norman Lloyd, and William Daniels, and I recall hearing of Denzel Washington's leaving the show at its conclusion to a big career in film. In this first season, Washington has a small role near the end of the season. The major players in story arcs for the first season are Ed Begley Jr., David Morse, Howie Mandel, Terence Knox, and Kim Miyori (who is not even in the main credits.)
The glory of the series was this huge cast, and a list of future great guest stars such as Tim Robbins and Tom Hulce, before Robbins went on to "Top Gun" and even bigger roles and Hulce went on to an Academy Award nomination for his role in Amadeus. The big cast meant you could have a wide variety of characters every week. Ed Begley was smart, but awkward and naïve with the demanding head of surgery (Daniels). David Morse was a good, contentious doctor, who stretched himself too thin. Terence Knox was an average resident, who could not deal with his family life. Howie Mandel was an excellent resident in the ER, but inconsiderate of his fellow doctors.
One character which deserves a lot of credit is the fictional hospital after which the series is named. It always stands as a Cinderella to the famous "Boston General", a fictionalization of "Massachusetts General" in Boston. I can't help thinking that just a little inspiration for the series came from the film "The Hospital" which also takes place in an older center city hospital. The exterior and the look of the corridors exude age.
Perhaps one of the best things about the series is that it is the "anti-House". People get punished for breaking rules and going off on their own way of doing things. At the same time, there are no genius doctors. The three senior staff members, played by Flanders, Lloyd, and Craig are very good, perhaps some of the best in Boston, but they are no Gregory House. We see the reality of the way things work in hospitals.
I would not say there are any supremely great episodes in Season 1, but the level of storytelling, the interlocking arcs, is consistently high, and things hang together better than they did in "Hill Street Blues" which ran at about the same time.